Isuzu 12-bolt Brake Problem - All please read

Having brake adjustment problems in a hybrid situation...

The Set-up…

’89 Jeep Wrangler YJ
Waggy 44 Front axle w/ discs
Isuzu Trooper 12-bolt Rear axle w/ discs
New 350 Brake Master Cylinder
New Rear Isuzu Rotors
New brake lines throughout
Proportioning Valve isolated from front brakes


The problem…

After swapping in the current axles mentioned above, to replace the factory Dana 30 and 35, and a brake bleed, my buddy went out for a test drive. When he hits the brake pedal, the front wheels lock up, while the rear ones just roll. (Test drive on packed snow and ice).

At first he thought the factory Jeep master cylinder was shot, and swapped in the current 350 unit. Same results. His next idea, was to try and swap the brake lines around at the master cylinder, thinking that if the rear locked, and the front didn’t, it would at least eliminate the under hood components (ie: Booster) as the culprit. Well, still the same problem.

We can’t figure out why the rear won’t lock up with the front. Is there a special way to bleed the Isuzu 12-bolt system? Are we just missing something? Maybe there's an adjustment to make the calipers engage better.

Any help will be appreciated.

Gary Graham
Arctic Offroad Secretary
Fairbanks Alaska
www.arcticoffroad.com

Btt

try to adjust the rear pressure regulator.
its located in the back. above the rear axle.in the floor not in the car. it is connected with the rear axle